title: Propagation of the sinus impulse into the Koch triangle and localization, timing, and origin of the multicomponent potentials recorded in this area.
abstract: BACKGROUND
  The presence of a conduction block at the level of the Koch triangle (KT) and the origin of the multicomponent potentials inside this area are controversial issues. We investigated the propagation of the sinus impulse into the KT and the characteristics of multicomponent potentials recorded in that area in patients with and without atrioventricular nodal reentrant tachycardia (AVNRT).
  
  
  RESULTS
  Thirty-two patients (16 with AVNRT, 16 without AVNRT) underwent a sinus rhythm electroanatomic mapping of the right atrium (RA). Conduction velocities in the RA and in the KT were evaluated quantitatively on activation maps and qualitatively on isochronal and propagation maps. The presence, location, and timing of different types of multicomponent potentials were evaluated. A mean of 149±44 points were sampled in the RA, whereas a mean of 79±21 points were collected inside the KT. Propagation block at the level of crista terminalis was not found in any patient, whereas slow conduction inside the KT was found in all (median conduction velocity, 122 cm/s [110 to 135 cm/s] outside KT versus 60 cm/s [48 to 75 cm/s] inside KT; P<0.0001). Jackman potentials were identified inside KT in almost all the patients and were invariably found on the line of collision between the wavefronts activating the KT in opposite directions.
  
  
  CONCLUSIONS
  No conduction block was detected inside the KT in patients with and without AVNRT. Conduction slowing was demonstrated during propagation of the sinus impulse inside the KT. The genesis of the Jackman potential may be related to the collision of the wavefronts activating KT in opposite directions.
authors.affiliation: Department of Cardiology, San Filippo Neri Hospital, Rome, Italy. cpandozi@libero.it
authors.forename: Claudio
authors.initials: C
authors.lastname: Pandozi
authors.forename: Sabina
authors.initials: S
authors.lastname: Ficili
authors.forename: Marco
authors.initials: M
authors.lastname: Galeazzi
authors.forename: Carlo
authors.initials: C
authors.lastname: Lavalle
authors.forename: Maurizio
authors.initials: M
authors.lastname: Russo
authors.forename: Angela
authors.initials: A
authors.lastname: Pandozi
authors.forename: Franco
authors.initials: F
authors.lastname: Venditti
authors.forename: Christian
authors.initials: C
authors.lastname: Pristipino
authors.forename: Brunella
authors.initials: B
authors.lastname: Verbo
authors.forename: Massimo
authors.initials: M
authors.lastname: Santini
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012384:Rome; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D009626:Terminology as Topic; D013997:Time Factors